Potentiation of hematopoietic cell migration with an IGF–interleukin‐3 fusion protein

A chimera of an N‐terminally modified insulin growth factor (IGF)‐II, NQPQMVHTY‐hIGF‐II(9–67) (BOMIGF), fused to interleukin‐3 (IL‐3) significantly improved the migration of CD34 + human hematopoietic cells with respect to the effects observed during co‐stimulation with BOMIGF and IL‐3. A phosphatidylinositol‐3 (PI‐3) kinase inhibitor specifically inhibited migration in the presence of the chimera, while no significant difference in the inhibition of migration was observed in the presence of a Rho kinase inhibitor. These results suggest a key role of the PI‐3 kinase pathway in the potentiation of migration caused by the linkage of BOMIGF and IL‐3.